The Hubble Space Telescope

Unlocking the Secrets of the Universe

Flight Operations Summary

Significant Spacecraft Anomalies: (The following are preliminary reports
of potential non-nominal performance that will be investigated.)
HSTARs:
13349 - SCI: Loss of Lock Caused Loss of STIS Science Data@145/0739z
COMPLETED OPS REQUEST:
19248-0 - Clear COS Event Flag 3 for prop 12810 visits 10-11@150/1946z
COMPLETED OPS NOTES:
none
FGS ACQ STATUS:
SCHEDULED SUCCESSFUL
FGS GSAcq 9 9
FGS REAcq 6 6
OBAD with Maneuver 6 6
SIGNIFICANT EVENTS:
The COS FUV Special Recovery activities (proposal 12810 visits 8 - 9) successfully completed today
without incident. The FUV was ramped to HVLow (-4069V/-4069V (100/100)) with the QE grid on, no
elevated counts or HV current transients were observed in the engineering telemetry during or after
the ramp. The STScI and MOSES2 Engineering Teams have examined the relevant telemetry and
confirmed all voltages, currents and temperatures were as expected. The voltage and current
monitors matched the signatures seen in SMOV. The COS Science Team at STScI has examined the
science data and DCE memory dumps and has found no anomalous behavior. No HV current transients or
unexpected elevated count rates were observed in the DCE memory dumps. The science data consisted
of a single 300 second dark exposure with the QE grid on at HVLOW. No comparison with SMOV data was
possible, since no darks at HVLOW were taken at that time. Comparison with similar data taken with
the QE grid off in 12810 shows similar behavior. The Engineering and Science Teams have given a
"Go" to proceed with visit 10 and 11. Visits 10 and 11 are scheduled for Wednesday May 30th (DOY
151). The COS event flag 3 was cleared @150/19:46 via OR 19248-0 -jb